Node.jsとsocket.ioでLine風チャットを作成してみた4

node.jsとsocket.ioを使用する機会があったので、簡単にチャットを作ることにしました。
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###作成イメージ
![2019-07-07_13h24_10.png](https://qiita-image-store.s3.ap-northeast-1.amazonaws.com/0/445571/360e43eb-8855-c981-2e00-529fcd35e606.png)
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###ディレクトリ
![2019-07-07_13h12_12.png](https://qiita-image-store.s3.ap-northeast-1.amazonaws.com/0/445571/10f924bf-7b2d-5e4a-dbc5-88f95f0e3c21.png)
***

###完成コード

```html:hello.html
<!DOCTYPE html>
<html>

<head>
    <meta charset="UTF-8">
    <title></title>
    <link rel="stylesheet" type="text/css" href="./Line.css">
    <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/socket.io/2.2.0/socket.io.js"></script>
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
    <script src="./Line.js"></script>
</head>

<body>
    <div class="line">
    </div>

    <div class="submit">
        <input class="form-control" id="msgForm" autocomplete="off" maxlength="120">
        <input type="button" id="sendButton" onclick="window.message()" value="送信">
    </div>

    <div class="file">
        <input type="file" name="upfile" id="upfile" accept="image/*" capture="camera" />
        <input type="button" onclick="upload()" value="送信">
    </div>
</body>

</html>
```

```CSS:hello.CSS
.line {
  overflow:scroll;
  float: left;
  width:750px;
  height:370px;
  padding: 20px 10px;
  max-width: 450px;
  margin: 15px auto;
  font-size: 14px;
  background: #7da4cd;
}

.joincomment{
  text-align:center; 
}

.others{
  display: inline-block;
  position: relative;
  left: -80px;
}

.icon{
	display: inline-block;
	border-radius: 50%;
	width: 40px;
	height: 40px;
	position: relative;
    top:10px;
    left:75px;
}

.name{
  display: inline-block;
  font-size: 12px;
  position: relative;
  top:-35px;
  left:90px;
}

.othercomment {
  display: inline-block;
  position: relative; 
  left:10px;
  margin: 0 0 0 50px;
  padding: 10px;
  max-width: 250px;
  border-radius: 12px;
  background: #edf1ee;
  text-align: left;

}

.othercomment:after {
  content: "";
  display: inline-block;
  position: absolute;
  top: 3px; 
  left: -19px;
  border: 8px solid transparent;
  border-right: 18px solid #edf1ee;
  -webkit-transform: rotate(35deg);
  transform: rotate(35deg);
}
.othercomment p {
  margin: 0;
  padding: 0;
}

.mycomment {
  margin: 10px 0;
  text-align: right;
}
.mycomment p {
  display: inline-block;
  position: relative; 
  margin: 0 10px 0 0;
  padding: 8px;
  max-width: 250px;
  border-radius: 12px;
  background: #30e852;
  font-size: 15px;
}

.mycomment p:after {
  content: "";
  position: absolute;
  top: 3px; 
  right: -19px;
  border: 8px solid transparent;
  border-left: 18px solid #30e852;
  -webkit-transform: rotate(-35deg);
  transform: rotate(-35deg);
}

.submit{
  position: relative;
  top: 450px; 
  left: -460px;
}

#msgForm{
  width:410px;
}


.file{
  position: relative;
  top: 460px; 
  left: -460px;
}
```

```javascript:Line.js
var socket = io.connect('http://localhost:3000');
var name = prompt('ニックネームを入力してください', '');
joinUser(name);

socket.on("server_to_client", function (data) {
    appendOtherMsg(data.otherMsg, data.name, data.img);
});

socket.on("server_to_client_join", function (data) {
    appendJoinMsg(data.join);
});

function appendJoinMsg(message) {
    $(".line").append('<div class="joincomment">' + message + '</div><br>');
    $('.line').animate({ scrollTop: $('.line')[0].scrollHeight }, 'fast');
}

function appendOtherMsg(message, name, img) {
    $(".line").append('<div class="others"><img src="' + img + '" class="icon"><span class="name">' + name + '</span><div class="othercomment"><p>' + message + '</p></div></div><br><br>');
    $('.line').animate({ scrollTop: $('.line')[0].scrollHeight }, 'fast');
}

function appendMyMsg(message) {
    $(".line").append('<div class="mycomment"><p>' + message + '</p></div><br>');
    $('.line').animate({ scrollTop: $('.line')[0].scrollHeight }, 'fast');
}

function message() {
    if ($("#msgForm").val() != '') {
        var message = $("#msgForm").val();
        appendMyMsg(message);
        $("#msgForm").val('');
        socket.emit("client_to_server", { message: message, name: name });
    }
}

function joinUser(name) {
    var selectRoom = 1;
    socket.emit("client_to_server_join", { room: selectRoom, name: name });
}

function upload() {
    var img = $("#upfile").val().split("\\");
    socket.emit("client_to_sever_upload", { img: './image/' + img.pop() });
}

$('#msgForm').keypress(function (e) {
    if (e.which == 13 && $("#msgForm").val() != ' ') {
        message();
        return false;
    }
});
```

```javascript:chatServer.js
var http = require('http');
var socketio = require('socket.io');
var server = http.createServer(function (req, res) {

}).listen(3000);

var io = socketio.listen(server);

io.sockets.on('connection', function (socket) {
    var room = '';
    var name = '';
    var img = './image/icon.jpg';

    socket.on('client_to_server_join', function (data) {
        room = data.room;
        name = data.name;
        socket.join(room);
        io.to(room).emit('server_to_client_join', { join: name + "さんが入室しました。" });
    });

    socket.on('client_to_sever_upload', function (data) {
        img = data.img;
    });

    socket.on('client_to_server', function (data) {
        socket.broadcast.to(room).emit('server_to_client', { otherMsg: data.message, name: name, img: img });
    });

    socket.on('disconnect', function () {
        if (name == '') {
            console.log("未入室のまま、どこかへ去っていきました。");
        } else {
            io.to(room).emit('server_to_client_join', { join: name + "さんが退室しました。" });
        }
    });
});
```

###感想
データベースなしで作成したため、画像の持ち方は悪いと思います。
CSSに関しては得意ではないので、都度修正してください。画面のサイズでUIが変わると思います。
参考程度にしてください。